In the shop, the towers on each block type is the number of that type you can have on the field; the towers in the top left is the total number of blocks you can have.
Hi, more players reported this as a bug. It's just imperfect AI. I'm currently working on it to improve the AI so it does not crash into airships or ground. I hope that that Red Baron will be beatable after AI upgrade :)
Could you try setting storage to unlimited in Firefox? That's looking to be the problem.